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Gain insights into designing scalable Angular applications. Learn about components, directives, routing, RXJS, forms, and Firebase authentication to develop rich, interactive web solutions.

Angular Designing and Architecting Web Applications.png

angular-starter-v5.tar.gz

Angular

Angular Install Dependencies

Angular with Relaunch

This course will teach you step-by-step how to design and architect large Angular applications. 

You’ll start with the basics: components, pipes, and directives. These are the building blocks of any Angular application, so you will get plenty of hands-on practice with this material. Next, you’ll ramp things up by stepping into modules, routing, and RXJS, where you’ll learn how to declaratively manage data and dive deep into observables.

In the latter half of the course, you’ll cover reactive and template forms (crucial for handling user data), as well as custom validators and setting up authentication with Firebase.

By the end of this course, you'll be able to design large, scalable applications, be able to develop rich interactive components, and you’ll really understand how Angular works under the hood.

Angular: Designing and Architecting Web Applications

Our service is ready. It's time to load it in the validator so that we can use it. 

# Using the service

In the `compromised-password.ts` file, we'll import the service and inject it into the validator.

import { AsyncValidator, FormControl } from '@angular/forms';
import { EnzoicService } from '../enzoic.service';

export class CompromisedPassword implements AsyncValidator {
  constructor(private enzoic: EnzoicService) { }

  validate = (control: FormControl) => {
    return this.enzoic.checkPassword(control.value);
  }
}


In the example above, we're injecting the service into the validator. Then, we're converting the `validate` function into an arrow function because validators are passed in as references. When we pass in a reference, the scope of the function is not bound to the object. If we want to reset the scope, we'll need to adjust the function into an arrow function. This will give us access to the `this` keyword, which we'll need if we want to use the service injected into the class.

In the function, we're calling the `checkPassword` method on the service. We're passing in the `control.value` property, which is where the password is stored. The value returned by the method will be an observable. However, we must return `null` or an object with properties to describe the errors.

We can change the output using operators. This is where things can get tricky. 

# Catching errors

Every API will different. We are at the mercy of the API we use because it may handle errors differently than other APIs.

According to the documentation, the response from the API will have a status code of `200` if the password is found to be compromised. If the password is safe, the response will have a status code of `404`. 

This can be problematic because we need to be able to tell the form control that the validation was a success. If an error is thrown, an object will be returned from the validator, and the form control may assume there's an error. 

We can fix this by catching an error. We are able to change the value that is received as an output when an error occurs. Let's update the `compromised-password.ts` file to the following:

In this lesson, we'll handle the response from the API.

First Steps

Our First Project

Component Basics

Pipes

Directives

Modules

Routing

Advanced Components

Services

RxJS

Reactive Forms

Template Forms

Custom Validators

Authentication

Conclusion

Handling the Response

Using the service